A tropical depression that crossed the Philippines earlier this week has entered Vietnamese waters and developed into a storm.
Named Haikui, it is the 13th storm so far this year in the South China Sea, known as the East Sea in Vietnam.
At 4 a.m. on Friday, the storm was 930 kilometers (577 miles) southeast of the Paracel Islands with a maximum wind speed of 75 km (46 miles) per hour, according to the National Center for Hydro-Meteorological Forecasting.
Over the next 24 hours, Haikui will move northwest at 20kph and will continue strengthening.
By 4 a.m. on Saturday, it will be 430km from the Paracel Islands with a maximum wind speed of 90kph.
Weather forecasters said as the storm is still far away, it is hard to tell exactly where it will head.
They said it could either continue to move northwest and weaken or head straight towards the central region, which is still reeling from a devastating typhoon that struck last week.
The central region has been ordered to monitor reservoirs and prepare for the worst case scenario.
If Haikui hits when the reservoirs are full, the region will face serious flooding. Cities and provinces across the region have been instructed to make plans to release water if needed.
The central region is still struggling to recover from Typhoon Damrey that made landfall on November 4, killing 106 people as of Wednesday.
Authorities said all efforts are being made to avoid flooding around the central city of Da Nang, where the Asia Pacific Economic Cooperation (APEC) Summit is taking place between November 6 and 11.
Cities and provinces in the region have already suffered from heavy downpours and flooding, partly due to dozens of reservoirs releasing water.